MFV v242732:

Merge the ZFS I/O deadman thread from vendor (illumos).
This feature panics the system on hanging ZFS I/O, helps debugging
and resumes failed service.

The panic behavior can be controlled with the loader-only tunables:
vfs.zfs.deadman_enabled (enable or disable panic on stalled ZFS I/O)
vfs.zfs.deadman_synctime (expiration time for stalled ZFS I/O)

By default, ZFS I/O deadman is enabled by default on amd64 and i386
excluding virtual guest machines.

Illumos ZFS issues:
  3246 ZFS I/O deadman thread

References:
  https://www.illumos.org/issues/3246

MFC after:	2 weeks

2 files changed, 62 insertions, 0 deletions

diff --git a/cddl/contrib/opensolaris/lib/libzpool/common/kernel.c b/cddl/contrib/opensolaris/lib/libzpool/common/kernel.c
index 56bf718..25dc520 100644
--- a/cddl/contrib/opensolaris/lib/libzpool/common/kernel.c
+++ b/cddl/contrib/opensolaris/lib/libzpool/common/kernel.c
@@ -45,6 +45,9 @@ int aok;
 uint64_t physmem;
 vnode_t *rootdir = (vnode_t *)0xabcd1234;
 char hw_serial[HW_HOSTID_LEN];
+#ifdef illumos
+kmutex_t cpu_lock;
+#endif
 
 struct utsname utsname = {
 	"userland", "libzpool", "1", "1", "na"
@@ -842,6 +845,28 @@ ddi_strtoull(const char *str, char **nptr, int base, u_longlong_t *result)
 	return (0);
 }
 
+#ifdef illumos
+/* ARGSUSED */
+cyclic_id_t
+cyclic_add(cyc_handler_t *hdlr, cyc_time_t *when)
+{
+	return (1);
+}
+
+/* ARGSUSED */
+void
+cyclic_remove(cyclic_id_t id)
+{
+}
+
+/* ARGSUSED */
+int
+cyclic_reprogram(cyclic_id_t id, hrtime_t expiration)
+{
+	return (1);
+}
+#endif
+
 /*
  * =========================================================================
  * kernel emulation setup & teardown
@@ -875,6 +900,10 @@ kernel_init(int mode)
 
 	system_taskq_init();
 
+#ifdef illumos
+	mutex_init(&cpu_lock, NULL, MUTEX_DEFAULT, NULL);
+#endif
+
 	spa_init(mode);
 }
 
diff --git a/cddl/contrib/opensolaris/lib/libzpool/common/sys/zfs_context.h b/cddl/contrib/opensolaris/lib/libzpool/common/sys/zfs_context.h
index 11fb681..469c59f 100644
--- a/cddl/contrib/opensolaris/lib/libzpool/common/sys/zfs_context.h
+++ b/cddl/contrib/opensolaris/lib/libzpool/common/sys/zfs_context.h
@@ -457,6 +457,9 @@ extern vnode_t *rootdir;
 
 extern void delay(clock_t ticks);
 
+#define	SEC_TO_TICK(sec)	((sec) * hz)
+#define	NSEC_TO_TICK(usec)	((usec) / (NANOSEC / hz))
+
 #define	gethrestime_sec() time(NULL)
 #define	gethrestime(t) \
 	do {\
@@ -624,6 +627,36 @@ typedef	uint32_t	idmap_rid_t;
 #define	ERESTART	(-1)
 #endif
 
+#ifdef illumos
+/*
+ * Cyclic information
+ */
+extern kmutex_t cpu_lock;
+
+typedef uintptr_t cyclic_id_t;
+typedef uint16_t cyc_level_t;
+typedef void (*cyc_func_t)(void *);
+
+#define	CY_LOW_LEVEL	0
+#define	CY_INFINITY	INT64_MAX
+#define	CYCLIC_NONE	((cyclic_id_t)0)
+
+typedef struct cyc_time {
+	hrtime_t cyt_when;
+	hrtime_t cyt_interval;
+} cyc_time_t;
+
+typedef struct cyc_handler {
+	cyc_func_t cyh_func;
+	void *cyh_arg;
+	cyc_level_t cyh_level;
+} cyc_handler_t;
+
+extern cyclic_id_t cyclic_add(cyc_handler_t *, cyc_time_t *);
+extern void cyclic_remove(cyclic_id_t);
+extern int cyclic_reprogram(cyclic_id_t, hrtime_t);
+#endif	/* illumos */
+
 #ifdef	__cplusplus
 }
 #endif